Nearly one in three public school students in New York City suffered from mental disorders six months after the Sept. 11 terror attacks, according to a new study released Tuesday.

The three most common disorders found were agoraphobia, or fear of being in public spaces where escape is difficult, separation anxiety and Post-Traumatic Stress Disorder, and these three generally occurred at more than triple the normal rate, researcher found.

The study was carried out six months after Sept. 11 by a team led by Christina Hoven, an assistant professor at Columbia University Medical Center and director of epidemiology at Columbia's Mailman School of Public Health.

Hoven's team surveyed more than 8,000 city public school students in grades four through 12 about six months after Sept. 11, and found that 28.6 percent had an anxiety disorder at the time.

If applied to the entire population of New York City children in grades 4-12, that figure translates into 204,829 school children suffering an anxiety disorder after Sept. 11.

These are internalized disorders, difficult for even an attentive parent or teacher to detect, Hoven said.

Hoven said she had hoped to continue the study over time, but was unable to do so. As for how the children are faring now, she speculated, "I would expect some of the children have gotten much worse, some are the same, and many have gotten better on their own."

Preliminary findings were made public in 2002, but the paper is being published for the first time in the May issue of Archives of General Psychiatry.